1. Field of the Invention
This invention relates to a nylon traveller for spinning machinery, including a ring spinning machine, a ring twisting machine, etc.
2. Description of the Prior Art
The recent tendency in spinning machinery is that the spindle speed has been increased more and more for raising the productivity of the spinning machinery. Also, there is an increased tendency to spin or twist yarn of high tension out of carbon fiber, ceramic fiber, etc. However, this tendency has caused trouble in that the temperature of a running traveller at the part where it makes contact with yarn and a ring rises higher than usual due to a large load between the traveller and yarn/ring and resultant frictional heat generated by the increase of frictional force.
In the case of nylon travellers made of nylon 6--6 which are generally used for ring spinning machines and ring twisting machines, these travellers do not have high heat-resistance (thermal deformation temperature under a constant load of 4.6 kg/cm.sup.2 is 235.degree. C. but under a constant large load it is 90.degree. C.) and therefore in the recent ring spinning and ring twisting operations where a large load is applied to running travellers, abrasion of travellers progresses rapidly, with the result of "yarn breakage", "yarn fluffing", "severing of traveller at yarn passing portion", etc. Thus, improvement of productivity and improvement of yarn quality are hindered. Since the conventional nylon traveller made of nylon 6--6 has crystalline grains of large diameter (10-20 .mu.m), namely, it is of coarse crystalline structure, it is not satisfactory in heat-resistance and abrasion-resistance.